Syngenta Field Report

The Syngenta Field Report features information and experts from Syngenta sharing observations about issues growers are dealing with in the fields.

Glyphosate-resistance spreading

Jan 08, 2010

Chuck Foresman

Glyphosate-resistance waterhemp lives in just over half of Missouri fields, according to Dr. Kevin Bradley, a weed scientist from the University of Missouri. During harvest of 2008, he collected weed seed across the state, and he evaluated that seed for glyphosate resistance in 2009.

Here are highlights from his study:
- Glyphosate-resistant waterhemp in the fields at harvest was found in 51% of the randomly sampled fields- Of the fields with glyphosate-resistant waterhemp, 53% had no other weeds present
- Palmer pigweed and giant ragweed were added to the list of confirmed glyphosate-resistant weeds in Missouri
- Missouri has Palmer pigweed, a weed related to waterhemp, in places that Dr. Bradley didn’t know it lived